ISSN:
1573-5060
Keywords:
alfalfa
;
genetics
;
heritability
;
trichomes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The presence of glandular trichomes may protect alfalfa (Medicago sativa L.) against certain stem-, leaf-, and fruit-eating insect pests. In order to determine appropriate breeding methods to select for this trait, this study characterized quantitative genetic parameters of erect glandular trichome density in `KS94GH6' diploid (2n=2x=16) alfalfa. Eight female and five male plants were crossed in a Design II mating to produce 40 full-sib families. Glandular trichome density was determined on these families under replicated greenhouse conditions in Las Cruces and Los Lunas, New Mexico, U.S.A. The effect of males was significant (p≤ 0.10) across the two environments. Variation among females was not significant within either location or across locations. The dominance genetic variance (σ2 D = 0.210) was greater than the additive genetic variance (σ2 A = 0.111). The average degree of dominance exceeded a value of `1' indicating that erect glandular trichome density in KS94GH6 may be influenced by digenic epistasis, and/or repulsion phase linkage disequilibrium. The large contribution of non-additiveeffects was reflected by a low narrow-sense heritability estimate (h 2 n = 0.25). The results indicate that further improvements in erect glandular trichome density in KS94GH6 alfalfa will require replicated progeny testing. Approaches to introgress this trait into cultivated tetraploid alfalfa are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1003785010499
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